A glass substrate is used in manufacturing a flat panel display such as a liquid crystal display apparatus. In a process for manufacturing a flat panel display, the glass substrate is mounted on a susceptor in a reactor vessel of a semiconductor manufacturing apparatus and subjected to film forming processing in order to form a semiconductor element such as a thin film transistor (TFT) on the surface of the glass substrate. The film forming processing is performed multiple times using a plurality of semiconductor manufacturing apparatuses in order to form a plurality of types of thin films on the glass substrate. Each time the film forming processing is performed, the glass substrate is removed from the susceptor. At this time, static electricity due to friction, that is, peeling electrification occurs between the metal surface of the susceptor on which the glass substrate has been mounted and the surface of the glass substrate, and static electricity accumulates in the glass substrate. Accordingly, a large amount of static electricity accumulates in the glass substrate subjected to the film forming processing multiple times.
In particular, the surface of a glass substrate constituted by alkali-free glass to be used in a liquid crystal display apparatus is easily electrified, and it is difficult to eliminate static electricity. When peeling electrification repeatedly occurs, the glass substrate is likely to stick to the metal surface of the susceptor due to the static electricity. Accordingly, when the glass substrate is removed from the susceptor, excessive force is applied to the glass substrate, and thus the glass substrate is sometimes broken. Moreover, the semiconductor element formed on the surface of the glass substrate is sometimes broken due to voltage generated by the accumulating static electricity caused by the peeling electrification. Furthermore, fine foreign matter such as dust or dirt sometimes attaches to the surface of the glass substrate due to the static electricity accumulating in the glass substrate.
Under such circumstances, manufacturing a glass substrate whose surface is unlikely to be electrified in the process for manufacturing a flat panel display has been proposed. For example, a glass substrate disclosed in Patent Literature 1 (JP 2005-255478A) has a device surface that is a surface on which electrode wires and various devices are formed and a roughening surface on a side opposite to the device surface. The roughening surface is a surface roughened by forming unevenness thereon through physical polishing or chemical processing and has an arithmetic mean roughness Ra of 0.3 to 10 nm. The electrification of the glass substrate is suppressed by performing roughening processing on the roughening surface.